Fixes the "Inconsistent UPS behaviour."

This eliminates the active UPS items, instead the items that use the UPS can be made active.

Items request charges of "UPS", which can be supplied by either normal UPS, advanced UPS or the UPS bionic (in that order).

The optical cloak and the power armor are a bit different now. They can be activated (if UPS are available and when they are worn), which makes the item active (but does change the item type).

Fixes #6205
Yes, but I've already broken it by removing the "_on" items. Adding another wrapper to fix this is possible, but I've decided against it as the current hack in savegame*.cpp is already ugly enough.